title: Antioxidant and cytotoxic properties of an aqueous extract from the Argentinean plant Hedeoma multiflorum.
abstract: BACKGROUND
  Hedeoma multiflorum Benth. (Lamiaceae) is widely used in Argentinean popular medicine for digestive and anti-spasmodic purposes. However, knowledge about its pharmacological properties has been poorly investigated.
  
  
  OBJECTIVE
  The antioxidant and cytotoxic properties of an aqueous extract from the plant were investigated for the first time.
  
  
  METHODS
  Scavenging of stable free radicals of 2,2-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS(+)) and 2,2-diphenyl-1-picryl hydrazyl (DPPH), reducing of ferric (III) iron of ferric reducing ability of plasma (FRAP) reagent, and inhibition of lipid peroxidation (LP) of human plasma and rat brain homogenates were assessed. Cytotoxicity was tested on human polymorphonuclear (PMN) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cytotoxicity was assessed by flow cytometric techniques.
  
  
  RESULTS
  Extract scavenged ABTS(+) and DPPH (1.78 and 0.78 µmol Trolox equivalent/mg dry extract, respectively) and reduced FRAP reagent (0.66 µmol ascorbic acid equivalent/mg dry extract). LP of human plasma and rat brain was also inhibited in a dose-dependent way (inhibitory concentration 50%=27.0 and 86.0 µg/mL, respectively). Extract is rich in polyphenol compounds (0.96 ± 0.08 µmol equivalent caffeic acid/mg dry matter). Treatment of PMN decreased significantly the cell ability to reduce the MTT salt and increased the hypodiploid nuclei from 4 to 18% quantified using propidium iodide (PI). In the annexin V-Fluorescein isothiocyanate (annexin V-FITC) assay, 26% of treated cells were annexin V-FITC positive and PI negative. Using the 3,3'-dihexyloxacarbocyanine iodide uptake method, the negative fraction of cells was calculated as 29%.
  
  
  CONCLUSIONS
  H. multiflorum extract was found to have a significant antioxidant and pro-apoptotic activities, and a great potential as a source of healthy products.
authors.affiliation: Facultad de Ciencias Médicas, Cátedra de Farmacología Básica, Universidad Nacional de La Plata, La Plata, Argentina.
authors.forename: Martín Miguel
authors.initials: MM
authors.lastname: Dadé
authors.forename: Guillermo Raúl
authors.initials: GR
authors.lastname: Schinella
authors.forename: Daniel Emilio
authors.initials: DE
authors.lastname: Fioravanti
authors.forename: Horacio
authors.initials: H
authors.lastname: Alfiotournier
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001118:Argentina; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005609:Free Radicals / Q000378:metabolism; D031336:Hedeoma / Q000737:chemistry*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D010949:Plasma / Q000378:metabolism; D051381:Rats; D014867:Water / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D010936:Plant Extracts; D014867:Water